For mounting a chip with a lot of pins such as a central processing unit (CPU) onto a circuit board, the general approach is to mount a socket with many pin slots onto the circuit board. Each pin slot has a conductive terminal coupling with the circuit board. The pins of the chip are inserted into the pin slots to be in contact with the terminals, to establish electric connection. However, merely having the pins inserted into the pin slots not necessary means that the pins and the terminals have formed a desired electric connection.
The terminal structure often determines whether a contact is good or poor. In general, especially for a CPU, the socket is covered by a sliding cap which has many through holes formed thereon. The sliding cap may be moved horizontally by a swinging control arm to position at a selected location. The pins of the chip have to be inserted into the through holes first, then are inserted into the pin slots of the socket. The horizontal movement of the sliding cap moves the pins close to the terminals so that the contact of the two is tight and secured to reduce defective connection. While such a design can reduce some defective contacts, the pins still might be tilted during insertion or horizontal movement and result in deformation or fracture of the pins or terminals. As a result, defective contact and connection still occurs.
As previously discussed, the key issue of the problems is the terminal structure. The present terminal generally is formed in U-shape or a variation under the same structure. A good contact between the pin and the terminal basically depends on the elasticity of the terminal structure. Due to a lack of suitable guiding means for insertion, or the structural problem, the possibility of a tilted pin to cause deformation or defective contact of the terminal is high. Moreover, the present terminal structure has to mate the pin slot. Hence product expandability and applicability is limited. Elements thus made cannot be commonly shared. As a result, they are not suitable for mass production and the cost is higher.